Depends on where you live; have tasted water in other parts of the country/world that had a definite 'ugh' factor.
Our water up here, thankfully, is good enough that from-the-tap routinely fools my water-snooty friends. Poured from 'brand name' re-used plastic bottles they don't know the difference!
Those bottles do make it easier to carry around tho'...
If your water has an ‘ugh’ factor, a simple Brita filter (or the like) will improve the taste a lot. We have pretty good tap water here; but, there’s always a bit of a chlorine taste, and sometimes silt or algae in the reservoir — the filter takes care of all that for a tiny fraction of the cost of bottled water.
That said — I don’t like bans.